Development of a low-cost semi-passive transponder for sensor applications at 2.4GHz

Development of a simple low-cost radio frequency identification (RFID) transponder for wireless sensor networks at 2.4 GHz is presented. The transponder is comprised of a rectangular patch antenna, RF modulating circuit and a low power mixed signal microcontroller from Texas Instruments. The transponder is powered by a 3 V pill-box battery and uses amplitude shift keying (ASK) backscatter modulation to communicate with a RFID reader. In this paper we present the design steps and measured results of the developed semi-passive RFID transponder.